Principles of multidetector-row computed tomography: Part 1. Technical design and physicotechnical principles [Grundlagen der Mehrzeilendetektor-Computertomographie: Teil 1: Technischer Aufbau und physikalisch-technische Grundlagen]
Stiller W.,Abteilung Radiologie
Radiologe | Year: 2011
Despite the unchanged retention of the fundamental technical and physical principles since its first clinical application in the year 1972, computed tomography (CT) constitutes a mainstay of present day radiological diagnostics. In conjunction with the sub-second gantry rotation times now achieved numerous technical improvements, such as helical scanning and the development of high-performance X-ray tubes as well as multi-row detectors with up to 320 rows allow large areas to be examined with high image quality within only a few seconds. On the basis of these advancements modern multidetector-row CT (MDCT) enables high-resolution slice or volume imaging of the anatomy as well as multiphase and perfusion examinations. An end to innovations in the field of MDCT is not yet foreseeable and further technical developments will open up new radiodiagnostic indications thereby broadening the spectrum of clinical applications of MDCT in the future. © 2011 Springer-Verlag.
Delorme S.,Abteilung Radiologie
Internist | Year: 2012
This is a review on the role of ultrasound for early detection and staging of cancer. In breast cancer screening ultrasound serves to clarify mammographically unclear lesions and is a primary screening tool for hereditary breast cancer. Renal neoplasms are commonly diagnosed as incidental sonographic findings and in this case are more often in a curable stage than symptomatic neoplasms. In chronic hepatitis or liver cirrhosis the annual incidence of hepatocellular cancer is more than 2% and ultrasound is used as a screening tool with 60% sensitivity and 97% specificity. According to the literature the sensitivity of native ultrasound for detecting metastases is 60% and the sensitivity of contrast-enhanced ultrasound (CEUS) is 79% or higher, i.e comparable with the sensitivity of contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI). Its role in staging is, however, limited as CT and MRI are necessary for local staging of the primary tumor and also include the liver. In the differential diagnosis of liver lesions the specificity of CEUS ranges from 82% to 99% depending on the lesion entity and is thereby comparable to contrast-enhanced CT. For staging of cervical lymph node metastases ultrasound is preferable to CT or MRI as the sensitivity lies between 79% and 90% and specificity is reported to be 90%. © Springer-Verlag 2012.
Busch H.-P.,Abteilung Radiologie
RoFo Fortschritte auf dem Gebiet der Rontgenstrahlen und der Bildgebenden Verfahren | Year: 2013
Hospitals around the world are under increasing pressure to optimize the economic efficiency of treatment processes. Imaging is responsible for a great part of the success but also of the costs of treatment. In routine work an excessive supply of imaging methods leads to an "as well aso" strategy up to the limit of the capacity without critical reflection. Exams that have no predictable influence on the clinical outcome are an unjustified burden for the patient. They are useless and threaten the financial situation and existence of the hospital. In recent years the focus of process optimization was exclusively on the quality and efficiency of performed single examinations. In the future critical discussion of the effectiveness of single exams in relation to the clinical outcome will be more important. Unnecessary exams can be avoided, only if in addition to the optimization of single exams (efficiency) there is an optimization strategy for the total imaging process (efficiency and effectiveness). This requires a new definition of processes (Imaging Pathway), new structures for organization (Imaging Center) and a new kind of thinking on the part of the medical staff. Motivation has to be changed from gratification of performed exams to gratification of process quality (medical quality, service quality, economics), including the avoidance of additional (unnecessary) exams. © Georg Thieme Verlag KG Stuttgart. New York.
Schulte-Baukloh H.,Abteilung Radiologie
Urologe - Ausgabe A | Year: 2012
Botulinum neurotoxin (BoNT) has become increasingly established in the treatment of neurogenic bladder dysfunctions over the last 12 years. Today it represents an alternative to conservative medical therapy and reduces the indications for broader surgical measures. Since September 2011, BoNT/A is approved for the use in neurogenic bladder disorders. This article therefore summarises the main findings once more, particularly with regard to practical application.The by far most commonly used BoNT subtype is botulinum neurotoxin A (BoNT/A), which has shown the most convincing effects after detrusor injections in the urological field. It unfolds its full effect after about 7 days. Subjective parameters, such as urination frequency, incontinence and quality of life are improved most substantially, which is objectively reflected by the increase in bladder capacity and the reduction of maximum detrusor pressure. Significantly decreasing effectiveness and necessity for repeated injections must be expected after about 9 months. Repeated applications have proven to be effective. Systematic side effects are rare and do not reach dramatic extents. The major urologic side effect, which is not uncommon, is the increase in residual urine, which can lead to urinary retention in patients with spontaneous voiding. © Springer-Verlag 2012.
Contrast in static images in clinical magnetic resonance imaging: Part 2: Sequences for various contrast weightings and applications [Bildkontraste bei statischen Aufnahmen in der klinischen Magnetresonanztomographie: Teil 2: Sequenzen für verschiedene Kontraste und Anwendungen]
Schick F.,Abteilung Radiologie
Radiologe | Year: 2013
The second part of this educational article focuses on sequence techniques in magnetic resonance imaging (MRI) and on suitable parameter sets for different contrast weightings. The content is based on the recently published part 1 of this educational article providing a survey on tissue properties relevant for most important contrast mechanisms. Characteristics of contrast weightings are presented in exemplary images recorded from healthy volunteers. Typical clinical applications of the most commonly used contrast weightings are described and discussed. Sequences for the following contrast weightings are included: proton density (density of hydrogen in small mobile molecules), relaxation times T 1 and T2, chemical shift (water and fat), effects of magnetic susceptibility, restricted diffusion of water molecules and magnetization transfer between macromolecules and water molecules. © 2013 Springer-Verlag Berlin Heidelberg.